Pokémon Stadium
 
 

Pokémon Stadium is one of the three games that's set to be released for N64.  In this game, you are able to see two (or more) characters go against each other.  The game features 40 built-in creatures that you can build up and send into battle.
 
The Japanese version of Pokémon Stadium is set to ship with an included 64 GB Pak. This device plugs into your controller's memory card slot, similar to the Rumble Pak. If you happen to be the happy owner of one of the Game Boy Pokémon games, plug that Game Boy cart into the 64 GB Pak, switch on Pokémon Stadium, and swap data between the two games. This way, you can bring the monsters you have discovered in the Game Boy Pokémon into the N64 game and view them in their 3D color glory. Pokémon Stadium lets you perform your multiplayer battles with a tad more graphic flair than the Game Boy can muster.
Using the included 64 GB Pak (in Japan), you can plug your Pokémon Game Boy cartridge into your controller, download your Pokémon into the N64, and duke it out with your friends with excellent 3D graphics. In addition to the battle features, Pokémon Stadium lets you play your Pokémon Game Boy game in emulation on the N64 and browse a Pokémon encyclopedia. Unfortunately, American Pokémon carts will not work with Pokémon Stadium, making it an import only for those playing the Japanese version of the game. 
Here are some of the options included with Pokémon Stadium:
Computer (Pasokon): There are four boxes with 30 slots each on the Game Boy Pokémon cartridge, so you can save the details of 120 monsters. Since that's not nearly enough memory to store all your horde,
this option allows you to transfer the info onto the cartridge itself. Transfer the monsters back and give them to your buddy.
 
Picture Book (Zukan): Allows the creation of an electronic "photo album" of your collection, categorizing the monsters according to the 151 different species. You can then view them in all their animated 3D polygon glory. The Zukan mode also includes maps that show the exact
locations and habitats of your monsters.
 
Quick Look (Ichiran): For a rapid review of your collection, this option lists the monster name, type, number, techniques, and other stats. It also
shows which items are stored in the computer (on the cart), so you can
employ the "Use" tool to quickly select the monster you wish to put into
combat.

GB (Game Boy): This function enables you to play the Game Boy Pocket Monsters game via the N64 (using the machine's controllers) on your TV screen.

Collection (Temochi): This is a database of all the monsters. Players can
check out the attributes and info of their creatures, as well as size up the opposition, and discover which attacks may have an advantage or be used against them in the upcoming battle.
 
Registration (Touroku): Import your friends' monsters and fight them as
many times as you want.

Tournament (Stadium): Send your monsters into battle against computer-controlled monsters or your friends' creatures.